Electromagnetic device



A. J. EAVES ELECTROMAGNETIC DEVICE Filed April 21, 1923 Nov. 24 ,4 1925-1362,94?

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AUGUSTUS J. EAVES, OF GSSIITING, NEW YORK. ASSIiNOR TO WESTERN ELECTRICCOMIANY, INCORPORATED, OF NEW" YORK, N. '51, A CQEPGRATION OF NEW YORK.

ELECTROIVIAGNETIC DEVICE.

Application filed April 21, 1323.

To u/l /10/11 i/ may concern:

Be it known that I, iiuo'usrus J. Eiivns, a citizen of United States,residing at ()ssinlug, in the county of ld estchester, State of NewYork, have invented certain new and useful Improvements inElcctromagiietic Devices, of which the following is a full, clear,concise and exact description.

This invention relates to electromagnetic devices and particularly topolarized telegraph sounders.

An object of the invention is the provision of a new and improved formof polarized sounder which has few and simple parts and which isreliable and eflicient in operation.

In accordance with the preferred form of the invention, a simple andetlicient means is provided for insuring the maintenance of a uniformhigh reluctance path between a permanent magnet and the core of anelectroniagnet.

Referring now to the drawings, Fig. 1 is a side elevation of theinvention in its prehrrrcd form. Fig. 2 is an end view of the structureof Fig. 1.

In accordance with the showing .in the dra wing, the polarized soundercomprises abase 7 on which there is mounted a plate 8 which is attachedto the base 7 by means of screws Sl t). Mounted on the plate 8 is a pairof electromagucts 1010. Each of these clectromagnets is provided witha'soft iron core 12 having its lower ends formed in the shape ofpole-pieces 13-13. Suitable screws are provided for clamping thepolepicces and the electromagnets to the plate 8.

Also mounted on the plate 8 is trunnion yoke Il/l carrying a trunnion 15supporting a sounding bar 19. Carried by the top of the trunnion yoke idis a projection having at its free end an aperture in which an adjusting screw 17 is threaded. To the adjusting screw 17 and titted in anotch in the sounding bar 19, is a lIialan-cing spring 18 which seiwesto balance the movement of the sound ing bar 19 with respect. to theassociated permanent magnet. Intern'iediate the ends of the sounding bar19 and just above the cores 12 of the electromagnet 10-10 is fired tothe sounding bar 19 an armature 20, which is attracted due to themagnetization induced in the cores upon the passage of a current throughthe windings of the electro magnets which have their ends connected toSerial No. 633,629.

terminals 1111. Also carried by the sounding bar 19 is an adjustablescrew 21 which is provided with a lock nut for limiting the downwardtravel of the sounding bar 19.

Also secured to the plate 8 is an anvil 22 which, like the sounding bar19, is provided with an adjustable screw -13 with a lock nut forlimiting the upward travel of the sounding bar 19.

The cores of the electromagnet are polar ized by means of a permanentL-shaped magnet 2st. The magnet 24: is mounted just above thepole-pieces 13 and has interposed therebetween a spacer 25 which in thepreferred form of the invention is of non-magnetic material such asbrass. The permanent magnet 24L is secured to the pole-pieces 13 bymeans of non-magnetic screws 26. The thickness of the spacer 2.5 varieswith the operating current of the circuit over which it is desired tooperate the sounder and the strength of the permanent magnet. It hasbeen found that for a current of substautially 6 mile the thickness ofthis spacer should be approximately For other operating currents thethickness of the spacer 25 will of course vary. The provision of aspacer 25 and the manner of mounting the permanent magnet 24; insuresthe maintenance of a uniform high reluctance path between the permanentmagnet and the pole-pieces 13 which is essential in the satisfactory andeliicient operation of such devices. Itis also to be noted that themounting of the permanent: magnet 24.- in the manner just described notonly insures a uniform high reluctance path between the permanent magnetand the pole-pieces, but also increases the resonant mass of thesounder. Such an arrangement in'iproves the quality and. the clearnessof the tones emitted upon the operation of the sounder.

The invention claimed. is:

1. In a polarized sounder, a base, an. electromaguct carried by saidbase having cores with pole-pieces secured thereto, a permanent magnetsecured to the pole-pieces, and a nonmagnetic spacer interposed betweensaid permanent magnet and pole-pieces for maintaining a uniform highreluctance path between it and the pole-pieces of the electromagnet.

A polarized sounder, comprising a base, an electromagnet mounted thereonhaving cores With pole-pieces secured thereto, a pen said permanentmagnet and said pole-pieces for insuring a uniform high reluctance pathbetween it and the cores of the electromagnet.

A polarized sounder, comprising a base, an eleetromagnet mounted thereonhaving a core with pole-pieces, an L-shaped perinareeaea'z' ucut magnetrigidly secured to said polepieces, and a strip of non-magnetic materialinterposed between said permanent magnet and said pole-pieces forinsuring a uniform hi gh reluctance path between it and the cores of theelectroinagnet.

In Witness whereof, I hereunto subscribe my name this 19 day of April,A. D. 1923.

AUGUSTUS J. EAVES.

